Engineered materials with controlled or unique structural attributes have found application in biomedical, military, filtration, catalyst, optics, and electronic fields. Researchers have, therefore, devoted their efforts into developing new fabrication technologies throughout the last decade. Specifically, the fundamental understanding and development of nano-sized materials have become an area of increasing popularity.
A nanometer is a billionth of a meter, or 10−9 m. Nanotechnology is the study and use of materials, devices, and systems of the scale of about one nanometer up to about 100 nanometers. One reason for the interest in materials of this size is the discovery that some essential properties of materials, such as strength and fatigue, are nonlinearly and individually based on the microstructure of materials. Another major driving force behind the interest in nanotechnology is the desire to build smaller, lighter, stronger, and faster devices. If researchers can learn to manipulate individual atoms on the nanometer scale, some experts believe that the results could lead to a revolution in computing, electronics, energy, materials design, manufacturing, medicine, and numerous other fields.
Electrospinning is a non-conventional fiber fabrication technique that can be used to produce fibers with diameters on the nanometer scale. It is also useful for the production of microfibers, which have larger diameters than nanofibers (from about 0.1 microns to several tens of microns). The vast majority of research and development of electrospinning has viewed the technique as a terminal process in the fabrication of fibers. By way of example, investigators have studied various polymer systems for “spinnability”, characterized the fiber surfaces and dimensions, examined the topology, and performed systematic studies of processing variables to improve fundamental understanding of the process and the fibers produced. However, extremely little has been done in the area of using electroprocessing as a precursor to subsequent processing steps.
Despite the developments to date, there remains a need for electroprocessing techniques that provide an attractive avenue for fabrication of novel materials with enhanced or “tunable” characteristics not obtainable by other means. Preferably, such techniques would use electroprocessing to produce fibers and materials of nano- or micro-scale dimensions, which are subjected to further processing to create materials tailored to specific applications of interest. More preferably, it would be desirable to develop material fabrication techniques in which electroprocessing is used as a precursor step to subsequent processing steps.